State governments in Australia have been warned that a funding row threatens "catastrophe" for one of the country's most important river systems.

Years of excessive irrigation and drought have left the Murray-Darling river basin in crisis.

A decision by officials in New South Wales and Victoria not to commit extra money to help its revitalisation has provoked much anger.

The river basin snakes across four states in south-eastern Australia.

It is one of the country's most important water courses, but is in serious ill health.

Rises in salinity levels, drought and too much irrigation have been blamed.

Who pays

A historic rescue plan announced last year received widespread approval.

But there is now serious disagreement between state governments about how much extra money is needed and who should pay for it.

South Australia has accused New South Wales and Victoria of being bloody-minded and of putting the restoration of the river basin in jeopardy.

The row comes as a major study reveals more problems for the river basin. It claims that excessive logging and grazing in adjoining forests and wetlands have caused a rapid environmental decline.

Campaigners have insisted that spending more money increasing the flow of water in the Murray-Darling basin without protecting the trees and plants on its banks is short-sighted and will do nothing to guarantee its long-term sustainability.